ISO is a camera setting that brightens or darkens a photo in the most basic sense. Your images will get increasingly brighter as you increase the ISO setting. As a result, ISO can assist you in capturing photographs in low-light situations or allowing you to be more flexible with your aperture and shutter speed settings.
The sensitivity to light of your camera, whether it's on film or a digital sensor, is measured in ISO. A lower ISO value indicates that the camera is less sensitive to light, whereas a higher ISO indicates that the camera is more sensitive to light. Set your ISO to its default value and your shutter speed to whatever level gives you the best results. If your subject is fuzzy, gradually increase the ISO while using a quicker shutter speed until the motion blur is gone.
However, increasing your ISO has drawbacks. A photograph taken with a high ISO will have a lot of grain, also known as noise, and may be unusable. As a result, increasing the ISO to brighten a photo is always a trade-off. Only increase the ISO if you are unable to brighten the image using the shutter speed or aperture.
If, for example, a longer shutter speed would result in a blurry subject, you should select a faster shutter speed.
ISO 100 (low ISO)
ISO 6400 (high ISO)
ISO 3200 has significantly more noise than an SO 200 shot. This is why, unless circumstances dictate it, you should avoid using high ISOs wherever possible.
When should high ISO be used?
Even though using low ISO is preferable, there will be occasions when a high ISO is required to shoot a good photo in the first place. The basic reason for this is that you will frequently be fighting motion blur, and you will have to choose between a sharp photo at a high ISO and a distorted photo at a low ISO.
Some photographers believe that using Base ISO 100% of the time is the best method to obtain high-quality photographs. You may find yourself in situations when you have no choice but to use a higher ISO.
Clearing up the myths & misconceptions
There are a lot of misconceptions about ISO, including some that are quite common. We'll quickly answer some of those issues in this section so that you're not misled about this topic in the future.
ISO is more accurately described as "mapping," in that it tells your camera how bright the output photo should be given a specific input exposure.
Raising your ISO in the camera provides better image quality and it isn't a tool for brightening your photo.
Low ISOs produce the greatest results, and using a tripod eliminates the risk of camera shake.
The ability to capture the action is crucial in sports. If the light is low, use whatever ISO you need because noise is secondary.
This allows for a shorter exposure, which reduces the amount of movement in the sky.
Low light / candid
The most important things are to acquire clear shots and maintain the mood.
Twilight / wildlife
Modern cameras have revolutionised low-light wildlife photography.
The sensitivity of many full-frame cameras means that you can now shoot things you can't see.